"Illness doesn't respect working hours. Heart attacks, major accidents, babies — these things don't just come from nine to five… With a future Conservative government, we would have a truly seven-day NHS," Cameron said at Conservative party's conference in Manchester.
Cameron added that the goal is to make the NHS services available for everyone in the country seven days a week by 2020, "the first country in the world to make this happen."
Cameron's "7-day-NHS" pledge comes as a response to a Friday statement by Labour leader Ed Miliband who promised to cap profits of private health companies.
The Conservative Party, headed by Prime Minister David Cameron and the Labour party led by Ed Miliband are the two major rivals in the general elections in the United Kingdom that are scheduled for May 7, 2015.
The NHS is a crucial issue in the run-up to the election.